As part of the process to create architectural visualization, we have to deal not only with geometrical polygon modeling, but also with organic surfaces. Some of those organic surfaces are required to create landscapes for our projects, which are important to create a context to the 3d model. If you want to learn an interesting way to create landscapes, you should take a look on the tutorial below from an artist called Jahnu Best, where he shows us how to create a landscape using displacement maps.
The artist uses an Add-on from Blender called ANT Landscape that was showed here on Blender3DArchitect, but with Blender 2.4x. Funny how time goes by!